It is well known that in some geographical locations the operation of terminal equipment connected to a telephone line can be disturbed by radio emissions or by electrostatic discharges.
Further, although protection devices for providing protection against voltage surges are generally provided at telephone exchanges, devices for providing such protection against voltage surges (which are usually caused by lightning) are not generally provided on subscriber premises.
An aim of the invention is to protect a subscriber against disturbances due to radio frequencies.
Another aim of the invention is to protect a subscriber against voltage surges. Naturally both types of protection may optionally be provided simultaneously.
Another aim of the invention is to make a device available for a subscriber seeking protection, which device is compact, very simple to use, and does not require any modification to the terminal equipment(s) to be protected.